Synthesis method of high-purity S-2-chloro-1-(2, 4-dichlorophenyl) ethanol

Abstract

The invention relates to the technical field of chemical synthesis, in particular to a synthesis method of high-purity S-2-chloro-1-(2, 4-dichlorophenyl) ethanol, which comprises the following steps: by taking 2, 2 '4'-dichloroacetophenone as a raw material, adding a novel chiral ligand, nitrogen-doped nano titanium dioxide and ionic liquid, and under the catalysis of an immobilized enzyme, enabling hydrogen to participate in reaction; the reaction is assisted by pulse-type ultrasonic waves, and conditions such as temperature and pressure are controlled; and after the reaction is finished, carrying out reduced pressure distillation to remove the solvent, and then carrying out gradient elution purification by using a silica gel column chromatography to obtain the final product with the purity of more than or equal to 99.5% and the R-isomer impurity of less than or equal to 0.05%. The synthesis method has obvious advantages; special raw materials are added to improve the reaction effect, the pulsed ultrasound and immobilized enzyme technologies improve the efficiency and reduce the cost, and the gradient elution purification effect is good; the prepared product is high in purity, and can be used for improving the medicine quality, the medicine stability and the bioavailability when being used for pharmacy.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical synthesis, and specifically to a method for synthesizing high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol. Background Art

[0002] As an important pharmaceutical intermediate, S-2-chloro-1-(2,4-dichlorophenyl)ethanol plays a crucial role in the research and production of cardiovascular disease treatment drugs and antibacterial drugs. With the continuous improvement of the requirements for disease treatment effects and drug safety in modern medicine, the requirements for the purity of this intermediate are becoming increasingly stringent. High-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol can significantly improve the quality and efficacy of downstream drugs and reduce potential adverse reactions caused by impurities.

[0003] However, the current synthesis of S-2-chloro-1-(2,4-dichlorophenyl)ethanol faces many challenges. Traditional synthesis methods usually use 2,4-dichloroacetophenone as the starting material for reduction reactions, but there are serious selectivity problems during the reaction process, making it difficult to efficiently obtain high-purity target products. For example, in the classical chemical reduction method using reducing agents such as metal hydrides, although the reduction reaction can be achieved, a large amount of R-isomer impurities will be produced, resulting in a product purity of only about 95%, far from meeting the strict requirements for raw material purity in the high-end pharmaceutical field. This not only increases the complexity and cost of subsequent purification processes but also may affect the quality and safety of the final drug due to the residual impurities.

[0004] In terms of reaction catalysts, it is difficult to balance the activity and selectivity of conventional catalysts. Some common enzyme catalysts have good chiral selectivity but low catalytic activity, long reaction times, and low production efficiency. For example, when ordinary lipase catalyzes this reaction, the reaction time may be as long as dozens of hours, which greatly limits the efficiency of large-scale industrial production and increases production costs.

[0005] In addition, there are also deficiencies in the optimization of the reaction system. In traditional reaction systems, the solubility and mass transfer efficiency of reactants are not high, resulting in limited reaction rates. At the same time, there are no effective monitoring means during the reaction process, making it impossible to accurately control the reaction process, further affecting the quality and yield of the product.

[0006] In the product purification section, existing purification methods also have many defects. Simple distillation, crystallization and other methods are difficult to effectively remove R-isomer impurities and other trace impurities. Although silica gel column chromatography can achieve a certain degree of separation and purification, the selection of eluents and elution methods are relatively single, and the separation effect is limited, making it difficult to increase the product purity to more than 99%.

[0007] With the rapid development of the pharmaceutical industry, the demand for S-2-chloro-1-(2,4-dichlorophenyl)ethanol continues to grow, and higher requirements are placed on its purity and quality stability. Therefore, developing an innovative synthesis method for high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol to overcome the defects of traditional methods and improve product purity and production efficiency has become an important issue to be solved in the current chemical synthesis field and the pharmaceutical industry. Summary of the invention

[0008] 1. Technical issues to be resolved

[0009] In view of the deficiencies in the prior art, the present invention provides a method for synthesizing high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol.

[0010] (II) Technical solution

[0011] A method for synthesizing high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol, wherein the structure of the S-2-chloro-1-(2,4-dichlorophenyl)ethanol is:

[0012]

[0013] It is characterized by comprising the following steps:

[0014] Raw material preparation: 2,2',4'-trichloroacetophenone is used as the starting material. The structural formula of the 2,2',4'-trichloroacetophenone is:

[0015]

[0016] Adding 0.5%-2% of a novel chiral ligand (S)-3,3'-di(trifluoromethyl)binaphtholphosphonate by mass fraction, adding 0.1%-0.5% of a nitrogen-doped modified nano titanium dioxide catalyst, and at the same time, adding 0.05%-0.2% of an ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate by mass fraction; adding tetrahydrofuran as a solvent in the reaction system, and the molar ratio of 2,2',4'-trichloroacetophenone to tetrahydrofuran is 1:(5-8);

[0017] Reaction process: Add the above raw materials and solvent into the reaction container, introduce hydrogen, control the hydrogen pressure at 0.5-1.5MPa, maintain the reaction temperature at 25-40°C, and react under the catalysis of immobilized lipase. The following reactions occur during the reaction:

[0018]

[0019] During the reaction, pulsed ultrasonic waves are used to assist the reaction. The ultrasonic frequency is 20 - 40 kHz, the power is 100 - 300 W, and the pulse time is 20 s - 30 s for on-time and 10 s - 20 s for off-time.

[0020] Product purification: After the reaction, the solvent tetrahydrofuran is removed by vacuum distillation. The distillation temperature is controlled at 40 - 60 °C, and the vacuum degree is 0.08 - 0.09 MPa. Then, the remaining product is further purified by silica gel column chromatography. The eluent is a mixed solution of n-hexane and ethyl acetate, and the volume ratio of n-hexane to ethyl acetate is (3 - 5):1. During the purification process, first elute with n-hexane:ethyl acetate = 5:1 for 3 - 5 column volumes, and then gradually adjust the ratio to 3:1 and continue to elute to obtain S-2-chloro-1-(2,4-dichlorophenyl)ethanol with a purity ≥ 99.5%, where the R-isomer impurity ≤ 0.05%.

[0021] Preferably, the synthesis method of the novel chiral ligand (S)-3,3'-bis(trifluoromethyl)-1,1'-binaphthyl phosphate is as follows: React (S)-3,3'-bis(trifluoromethyl)-1,1'-binaphthol with phosphorus oxychloride under a mixed catalytic system of anhydrous pyridine and N,N-dimethylformamide. The molar ratio of (S)-3,3'-bis(trifluoromethyl)-1,1'-binaphthol, phosphorus oxychloride, anhydrous pyridine, and DMF is 1:(1.2 - 1.5):(2 - 3):(0.5 - 1). The reaction temperature is 50 - 70 °C, the reaction time is 6 - 8 hours, and microwave-assisted heating is used during the reaction with a power of 200 - 300 W.

[0022] Preferably, the preparation method of the nitrogen-doped modified nano-titanium dioxide catalyst is as follows: Mix nano-titanium dioxide and urea at a mass ratio of 1:(0.2 - 0.5), and calcine in a nitrogen atmosphere at 400 - 500 °C for 3 - 4 hours. During the calcination process, the heating rate is 5 - 10 °C / min.

[0023] Preferably, the preparation method of the immobilized enzyme is as follows: Perform surface amination treatment on the mesoporous silica material in an ethanol solution of 3-aminopropyltriethoxysilane (APTES). The concentration of the APTES ethanol solution is 5% - 10%, the treatment temperature is 60 - 80 °C, and the treatment time is 2 - 3 hours. Then, mix the aminated mesoporous silica material with lipase CAL-B in a buffer solution with a pH value of 7 - 8. The mass ratio of lipase CAL-B to the aminated mesoporous silica material is 1:(5 - 10), and stir and react at 25 - 30 °C for 12 - 24 hours.

[0024] Preferably, during the reaction, the reaction progress is monitored in real time by an online Raman spectrometer, and the reaction intermediates and by-products are analyzed in combination with a gas chromatography-mass spectrometer. When the characteristic Raman peak intensity of 2,2',4'-trichloroacetophenone in the reaction system decreases to 10%-15% of the initial intensity, and the GC-MS detects that the content of the target product reaches 90%-95%, the reaction is determined to be complete.

[0025] Preferably, in the silica gel column chromatography, the particle size of the silica gel is 100-200 mesh, the ratio of column length to inner diameter is (15-20):1, and during the column packing process, the column is packed by a homogenization method, the homogenization solvent is n-hexane, and the column packing pressure is 0.5-1 MPa.

[0026] Preferably, high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol is prepared according to any of the above-mentioned synthesis methods.

[0027] Preferably, the high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol is used in the preparation of drugs for treating cardiovascular diseases or antibacterial drugs. In the preparation process, microcapsule embedding technology is used to make it into a microcapsule dosage form. The microcapsule wall materials are gelatin and gum arabic. The mass ratio of gelatin to gum arabic is 1:(1-2). The microcapsules are prepared by complex coacervation method, which can improve the stability and bioavailability of the drug.

[0028] (III) Beneficial technical effects

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. In terms of raw material selection and reaction system optimization, the added new chiral ligand (S)-3,3'-di(trifluoromethyl)binaphtholphosphonate greatly enhances the chiral induction effect due to its unique trifluoromethyl structure, making the optical purity of the S-2-chloro-1-(2,4-dichlorophenyl)ethanol generated by the reaction higher, and the impurity content of the R-isomer is significantly reduced. The purity of the final product can reach more than 99.5%, far exceeding the traditional method; the nitrogen-doped modified nano-titanium dioxide (N-TiO2) catalyst changes the electronic structure, improves the catalytic activity and selectivity, and the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF4) improves the solubility and mass transfer performance of the reaction system. The three work synergistically to effectively increase the reaction rate and shorten the reaction time. Compared with the traditional method, the reaction time is shortened by 30%-50%.

[0031] 2. Pulse ultrasound-assisted and immobilized enzyme technology is used. Pulse ultrasound promotes the dispersion and mass transfer of reactants, avoids the influence of long-term ultrasound on enzyme activity, and immobilized enzyme enhances the stability and reusability of enzyme, which can be reused 5-8 times, reducing production costs;

[0032] 3. The silica gel column chromatography with gradient elution was adopted. First, elute for 3 - 5 column volumes at a specific ratio, and then adjust the ratio to continue eluting, which effectively improves the separation effect, reduces the residual impurities while ensuring high purity of the product;

[0033] 4. When high - purity S - 2 - chloro - 1 - (2,4 - dichlorophenyl) ethanol is used in the preparation of cardiovascular disease treatment drugs and antibacterial drugs, it can significantly improve the quality and efficacy of the drugs and reduce the adverse reactions that may be brought by impurities. During the drug preparation process, the micro - capsule embedding technology is adopted to make a micro - capsule dosage form, which improves the stability and bioavailability of the drug, provides high - quality raw materials for the pharmaceutical field, and has significant economic and social benefits. Brief Description of the Drawings

[0034] Figure 1 is the flow chart of the synthesis method of high - purity S - 2 - chloro - 1 - (2,4 - dichlorophenyl) ethanol proposed by the present invention;

[0035] Figure 2 is the columnar comparison chart of the product purity of the examples and the comparative examples;

[0036] Figure 3 is the broken - line comparison chart of the R - isomer impurity content of the examples and the comparative examples. Detailed Description of the Invention

[0037] Example 1

[0038] Raw material preparation: Weigh 100 g of 2,2’,4’ - trichloroacetophenone and place it in a dry 500 - mL three - necked flask; Measure 500 mL of tetrahydrofuran and add it to the flask. The molar ratio of 2,2’,4’ - trichloroacetophenone to tetrahydrofuran is 1:6; Weigh 1.5 g of (S) - 3,3’ - bis(trifluoromethyl)binaphthylphosphate, 0.3 g of nitrogen - doped modified nano - titanium dioxide, and 0.1 g of 1 - butyl - 3 - methylimidazolium tetrafluoroborate and add them to the flask, and stir evenly;

[0039] Reaction process: Install the three - necked flask on the reaction device, introduce hydrogen gas, and adjust the pressure to 1.0 MPa; Turn on the temperature control device and maintain the reaction temperature at 30 °C; Add 0.5 g of the immobilized enzyme composed of lipase CAL - B and mesoporous silica material, turn on the pulsed ultrasonic device, set the frequency to 30 kHz, the power to 200 W, and the pulse time to 25 s on and 15 s off; During the reaction process, monitor the characteristic Raman peak intensity of 2,2’,4’ - trichloroacetophenone with an on - line Raman spectrometer every 1 hour, and regularly take a small amount of the reaction solution for analysis by gas chromatography - mass spectrometry;

[0040] Product purification: After reacting for 10 hours, the Raman peak intensity decreased to 12% of the initial value, and the content of the target product detected by GC-MS reached 93%, indicating that the reaction was completed; the reaction solution was transferred to a rotary evaporator, and tetrahydrofuran was removed by vacuum distillation at 45 °C and 0.085 MPa; the remaining product was purified by silica gel column chromatography, with a silica gel particle size of 150 mesh and a column length to inner diameter ratio of 18:1; first, elute with n-hexane:ethyl acetate = 5:1 for 4 column volumes, and then adjust the ratio to 3:1 and continue eluting; collect the eluate, concentrate it under reduced pressure and dry it to obtain the product;

[0041] Product detection: The purity of the product was detected by high performance liquid chromatography, and the purity calculated by the area normalization method was 99.6%, and the content of R-isomer impurities was 0.04%; the structure of the product was confirmed by 1H NMR and mass spectrometry, which was consistent with the structure of the target product.

[0042] Example 2

[0043] Raw material preparation: Take 120 g of 2,2’,4’-trichloroacetophenone and put it into a 600 mL three-necked flask, add 600 mL of tetrahydrofuran, with a molar ratio of 1:6.5; weigh 2.0 g of TFM-BINOL-P, 0.4 g of N-TiO2, and 0.15 g of [BMIM]BF4, and stir and mix evenly;

[0044] Reaction process: Connect the reaction device, introduce hydrogen until the pressure reaches 1.2 MPa, and control the temperature at 35 °C; add 0.6 g of immobilized enzyme, turn on the pulsed ultrasound, with a frequency of 35 kHz, a power of 250 W, and a pulse time of 30 s on and 20 s off; regularly monitor the reaction with a Raman spectrometer and GC-MS;

[0045] Product purification: After reacting for 8 hours, carry out vacuum distillation and silica gel column chromatography purification according to the method of Example 1, with a silica gel particle size of 180 mesh and a column length to inner diameter ratio of 19:1, and the same operation for the eluent ratio and elution column volume;

[0046] Product detection: After detection, the product purity was 99.7%, and the content of R-isomer impurities was 0.03%, 1 The structure was confirmed to be correct by 1H NMR and MS.

[0047] Example 3

[0048] Raw material preparation: Weigh 80 g of 2,2’,4’-trichloroacetophenone and place it in a 400 mL three-necked flask, add 400 mL of tetrahydrofuran, with a molar ratio of 1:5.5; weigh 1.0 g of TFM-BINOL-P, 0.2 g of N-TiO2, and 0.08 g of [BMIM]BF4, and stir evenly;

[0049] Reaction process: Install the reaction device, introduce hydrogen to make the pressure reach 0.8 MPa, and control the reaction temperature at 28 °C; add 0.4 g of immobilized enzyme, turn on the pulsed ultrasound with a frequency of 25 kHz and a power of 150 W, and the pulse time is 22 s on and 12 s off; monitor the reaction as specified;

[0050] Product purification: After 12 hours of reaction, perform vacuum distillation (50 °C, 0.082 MPa) and silica gel column chromatography purification (silica gel particle size 120 mesh, column length to inner diameter ratio 16:1, the operation of the eluent ratio and the elution column volume is the same as before);

[0051] Product detection: The product purity is 99.5%, the content of R-isomer impurities is 0.05%, and the structure is confirmed to be correct by 1 1H NMR and MS;

[0052] Comparative example

[0053] Raw material preparation: Weigh 100 g of 2,2’,4’-trichloroacetophenone and put it into a 500 mL three-necked flask, add 500 mL of tetrahydrofuran; no new chiral ligand, nitrogen-doped nano-titanium dioxide and ionic liquid are added;

[0054] Reaction process: Introduce hydrogen to a pressure of 1.0 MPa and a temperature of 30 °C, add 0.5 g of unimmobilized ordinary lipase CAL-B, and do not use ultrasonic assistance; take samples regularly and analyze the reaction process by GC-MS;

[0055] Product purification: After 15 hours of reaction, perform vacuum distillation (45 °C, 0.085 MPa), and purify it by silica gel column chromatography (silica gel particle size 150 mesh, column length to inner diameter ratio 18:1, the eluent is n-hexane:ethyl acetate = 4:1, single ratio elution);

[0056] Product detection: The product purity is 97.0%, the content of R-isomer impurities is 1.5%, 1 1H NMR and MS confirm that the product is the target product, but the purity is relatively low.

[0057] Comparison of product purity and impurity content between the example and the comparative example:

[0058] sample Example 1 Example 2 Example 3 Comparative Example Purity (%) 99.6 99.7 99.5 97.0 Content of R-isomer impurity (%) 0.04 0.03 0.05 1.5

[0059] Conclusion: This table clearly shows the significant differences between the example and the comparative example in terms of product purity and R-isomer impurity content. The purity of the example is above 99.5% and the impurity content is extremely low; while the purity of the comparative example is only 97.0% and the impurity content is as high as 1.5%, highlighting the great advantages of the synthesis method of this patent in improving product purity and reducing impurities.

[0060] Comparison table of purification parameters between the example and the comparative example:

[0061]

[0062] Conclusion: In Examples 1-3, gradient elution with n-hexane / ethyl acetate (5:1 → 3:1) was adopted. By gradually reducing the polarity of the eluent, the target product and the R-isomer impurity were effectively separated, and the purity reached over 99.5%. On the contrary, in the comparative example, a single elution ratio (4:1) was used, resulting in more impurity residues (the content of R-isomer was 1.5%) due to insufficient polarity adjustment. In addition, the optimization of the silica gel column parameters further strengthened the mass transfer equilibrium and shortened the separation time. The vacuum distillation conditions (45-50 °C, 0.082-0.088 MPa) efficiently removed tetrahydrofuran under mild temperature and low pressure, avoiding thermal decomposition of the product. In summary, the synergistic effect of gradient elution and silica gel column can accurately separate chiral products, while the traditional single elution leads to a decrease in purity due to insufficient separation kinetics, demonstrating the key value of the optimized purification process for the preparation of high-purity chiral compounds.

[0063] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for synthesizing high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol, the structure of the S-2-chloro-1-(2,4-dichlorophenyl)ethanol being: It is characterized in that Comprising the following steps: Raw material preparation: Using 2,2’,4’-trichloroacetophenone as the starting material, the structural formula of the 2,2’,4’-trichloroacetophenone being: Adding a novel chiral ligand (S)-3,3’-bis(trifluoromethyl)binaphthol phosphonate TFM-BINOL-P with a mass fraction of 0.5%-2%, adding a 0.1%-0.5% nitrogen-doped modified nano-titanium dioxide N-TiO2 catalyst, and at the same time, adding an ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM]BF4 with a mass fraction of 0.05%-0.2%; in the reaction system, adding tetrahydrofuran as the solvent, and the molar ratio of 2,2’,4’-trichloroacetophenone to tetrahydrofuran being 1:(5-8); Reaction process: Adding the above raw materials and solvent into a reaction vessel, introducing hydrogen, controlling the hydrogen pressure at 0.5-1.5 MPa, maintaining the reaction temperature at 25-40 °C, and carrying out the reaction under the catalytic action of an immobilized lipase. The following reaction occurs during the reaction process: During the reaction process, pulsed ultrasonic waves are used to assist the reaction, the ultrasonic frequency is 20-40 kHz, the power is 100-300 W, and the pulse time is 20 s-30 s for opening and 10 s-20 s for closing; Product purification: After the reaction is completed, the solvent tetrahydrofuran is removed by vacuum distillation, the distillation temperature is controlled at 40-60 °C, and the vacuum degree is 0.08-0.09 MPa; then the remaining product is further purified by silica gel column chromatography, and the eluent is a mixed solution of n-hexane and ethyl acetate, and the volume ratio of n-hexane to ethyl acetate is (3-5):1; during the purification process, first elute with n-hexane:ethyl acetate = 5:1 for 3-5 column volumes, and then gradually adjust the ratio to 3:1 and continue to elute to obtain S-2-chloro-1-(2,4-dichlorophenyl)ethanol with a purity ≥99.5%, and the R-isomer impurity ≤0.05%.

2. The synthesis method of high-purity S-2-chloro-1-(2,4-dichlorophenyl) ethanol according to claim 1, characterized in that, The synthesis method of the novel chiral ligand (S)-3,3’-bis(trifluoromethyl)binaphthol phosphonate is: Reacting (S)-3,3’-bis(trifluoromethyl)binaphthol with phosphorus oxychloride under a mixed catalytic system of anhydrous pyridine and N,N-dimethylformamide, and the molar ratio of (S)-3,3’-bis(trifluoromethyl)binaphthol, phosphorus oxychloride, anhydrous pyridine and DMF being 1:(1.2-1.5):(2-3):(0.5-1), the reaction temperature is 50-70 °C, the reaction time is 6-8 hours, and microwave-assisted heating is carried out during the reaction process, with a power of 200-300 W.

3. The synthetic method of high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol according to claim 1, wherein The preparation method of the nitrogen-doped modified nano-titanium dioxide catalyst is: Mixing nano-titanium dioxide and urea in a mass ratio of 1:(0.2-0.5), calcining in a nitrogen atmosphere at 400-500 °C for 3-4 hours, and heating at a heating rate of 5-10 °C / min during the calcination process.

4. The synthesis method of high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol according to claim 1, wherein The preparation method of the immobilized enzyme is as follows: the mesoporous silica material is subjected to surface amination treatment in an ethanol solution of 3-aminopropyltriethoxysilane (APTES). The concentration of the APTES ethanol solution is 5%-10%, the treatment temperature is 60-80 °C, and the treatment time is 2-3 hours. Then, the aminated mesoporous silica material is mixed with lipase CAL-B in a buffer solution with a pH value of 7-8. The mass ratio of the lipase CAL-B to the aminated mesoporous silica material is 1:(5-10), and the mixture is stirred and reacted at 25-30 °C for 12-24 hours.

5. The synthesis method of high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol according to claim 1, characterized in that, During the reaction process, the reaction progress is monitored in real time by an online Raman spectrometer, and at the same time, a gas chromatography-mass spectrometry (GC-MS) instrument is used to analyze the reaction intermediates and by-products. When the characteristic Raman peak intensity of 2,2’,4’-trichloroacetophenone in the reaction system decreases to 10%-15% of the initial intensity and the content of the target product detected by GC-MS reaches 90%-95%, the reaction is determined to be completed.

6. The synthetic method of high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol according to claim 1, characterized in that, In the silica gel column chromatography method, the particle size of the silica gel is 100-200 mesh, and the ratio of the column length to the inner diameter is (15-20):

1. During the column packing process, the slurry packing method is used, the slurry solvent is n-hexane, and the packing pressure is 0.5-1 MPa.

7. A high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol prepared by the synthesis method according to any one of claims 1-6.

8. The application of the high-purity S-2-chloro-1-(2,4-dichlorophenyl)ethanol according to claim 7 in the preparation of drugs for treating cardiovascular diseases or antibacterial drugs. During the preparation process, the microencapsulation technology is used to make it into a microcapsule dosage form. The microcapsule wall material is selected from gelatin and gum arabic, and the mass ratio of gelatin to gum arabic is 1:(1-2). The microcapsules are prepared by the complex coacervation method, which can improve the stability and bioavailability of the drug.

Images